Drug Diffusion
Which pair of the following diffusion-based processes are the most closely related?
A) Osmosis and ultrafiltration
B) Ultrafiltration and dialysis
C) Reverse osmosis and dialysis
D) Osmosis and reverse osmosis
E) Osmosis and dialysis
E) Osmosis and dialysis (Passive diffusion)
What HLB value is considered hydrophobic?
x less than or equal to 9 (lipophilic)
Which of the following about polymers are true? (Select all that apply)
A) Creates inter-particle bridges
B) An intermediate amount of polymers helps with flocculation
C) Too little or too much polymers can separate the particles and not become flocculated
D) Polymers can act as a viscosity enhancing medium
A, B, C, and D (Polymers are an example of a structured vehicle--substance that helps make deflocculated suspensions)
Micromeritics is relevant in the study of all of the following dosage forms, EXCEPT:
A) Concentrated aqueous solutions
B) Extended-release tablets
C) Powdered dosage forms
D) Pharmaceutical suspensions
E) Immediate-release tablets
A) Concentrated aqueous solutions
Which commonly used parenteral products/preparations require using a filter?
A) SDV
B) MDV
C) Prefilled-syringes/cartridges
D) Ampule
D) Ampule
Solute diffusion through a “dense porous” membrane is dependent on:
A) Solubility of the solute in the membrane
B) Size/dimensions of the solute
C) Size/dimensions of the membrane
D) All of the above
E) b and c only
E) b and c only
[Capillary Tube Image in Word Doc]
B
[Image on Word Doc]
E) B and C only
For nonporous powdered particles,__________ density becomes numerically equivalent to
________ density.
A) true; bulk
B) granule, bulk
C) granule; true
D) bulk; true
E) bulk; granule
C) granule; true
True or false: BUD are based on product specific info and extensive studies.
FALSE, BUD based on if we do not have the product specific info
Drug release from an osmotic pump is influenced by which of the following:
A) pH of the stomach at the time of drug release
B) Fluid permeability of the semi-permeable membrane
C) Thickness of the stagnant liquid film that forms around the dosage form
D) a and c only
E) b and c only
B) Fluid permeability of the semi-permeable membrane
The required HLB for an o/w emulsion type intended for oral administration is 14.5. If the percentage of the emulsifier blend, consisting of Tween 60 and Span 80, was determined to 4% of the
total formulation’s weight, how much (in grams) of each emulsifier, respectively, should be used in preparing 1000 grams of the product?
(HLB for Tween 60 = 14.9; HLB for Span 80 = 4.3)
A) 38.5; 1.5
B) 31.1; 8.9
C) 19.5; 20.5
D) 9.8; 30.2
A) 38.5; 1.5
The surface free energy (ΔG) of particles in a suspension is governed by the following relationship: ΔG = γSL · ΔA
Based on ΔG analysis, which of the following suspension systems
would decrease the energy of the system? (Select all that apply)
A) Allowing particles to settle in the form of hard cake
B) Addition of flocculating agent, thereby forming a flocculated suspension
C) Addition of surfactant which acts as interfacial tension lowering agent
A, B, and C
[PDI Graph on Word Doc]
D) 0.3
[Diagram on Word Doc]
D) All of the above
Which of the following will enhance the diffusion rate for a drug molecule permeating through a given biological membrane? (Select all that apply)
A) 3-fold increase in the diffusion coefficient of the drug in this membrane
B) 2-fold increase in the membrane-solution partition coefficient of the drug
C) 25% increase in membrane thickness
A and B only
A newly formulated cosmetic product will spread easily over the skin surface if:
A) The newly created interfacial tension plus the surface tension of the product are smaller than that of the skin
B) The sum of the surface tensions of the product and skin are higher than that of the newly created interfacial tension
C) The tension at the interface created is smaller than the surface tension of the product and skin combined
D) The surface tension of the skin plus the tension at the interface created upon spreading are greater than the surface tension of the cosmetic product
E) The surface tension of the product is smaller than that of the skin
A) The newly created interfacial tension plus the surface tension of the product are smaller than that of the skin
Based off of the spreading equation: yS > (yL +yLS)
A coarse powder with a true density of 2.44 g/cm^3 and a mean diameter of 100 mcm was dispersed in a 2% carboxymethylcellulose dispersion having a density of 1.010 g/cm^3. The viscosity of the
dispersion medium at low shear rate was 2700 cp. Calculate the average velocity of sedimentation of the
powder. (g = 980 cm/sec^2)
A) 2.1 x 10^-3 cm/sec
B) 2.1 x 10^-1 cm/sec
C) 2.9 x 10^-6 cm/sec
D) 2.9 x 10^-4 cm/sec
D) 2.9 x 10^-4 cm/sec
[Table on Word Doc]
B) 178.6
The diffusion coefficient, D, of tetracycline in a hydroxylethyl methacrylate membrane is 8.2 x 10-6 cm^2/sec and the partition coefficient, Km, for tetracycline between the membrane and the drug reservoir is 8.4. If the membrane thickness, h, is 140 mcm, what is the permeability, P, of tetracycline in this system?
A) 6.89 x 10^-2 cm/sec
B) 4.92 x 10^-3 cm/sec
C) 1.06 x 10^-4 cm/sec
D) 9.64 x 10^-7 cm/sec
B) 4.92 x 10^-3 cm/sec
Drug dissolution is applicable to a drug in a(an) (Select all that apply):
A) Rectal suppository
B) Topical ointment
C) Oral tablet/capsule
D) Pediatric suspension
A, B, C, and D (Only one that does not apply: solutions)
[Properties vs SAA Graph on Word Doc]
C) Solubility
A suspension of azithromycin with an average particle diameter of 24 mcm was prepared and the suspended particles were found to have an average sedimentation rate of 8 x 10-5 cm/sec in water (η = 1 cps). If the particle size of the suspended particles was reduced to 2 mcm and glycerin (η = 200 cps) is used as the dispersion medium, what will be the new sedimentation rate, assuming no significant change in the density of the dispersion medium?
A) 3.8 x 10^-9 cm/sec
B) 3.0 x 10^-9 cm/sec
C) 2.8 x 10^-9 cm/sec
D) 2.0 x 10^-9 cm/sec
C) 2.8 x 10^-9 cm/sec
A sample of ceftriaxone powder has a true density of 3.50 g/cm3. When 375 g of this powder is placed in a graduated cylinder, the volume measured was found to be 200 mL. If 1 mL of this powder is to be mixed with 5 mL sterile water to prepare an IV injection, what will be the volume of this solution upon addition of the powder?
A) 5.6 mL
B) 5.5 mL
C) 5.4 mL
D) 5.2 mL
B) 5.5 mL
A powdered drug sample weighing 1000 mg (particles assumed to be spherical in shape) was introduced to 500 cm^3 of 0.1 N HCl as the dissolution medium in a paddle-type dissolution apparatus at
37ºC. The dissolution rate data were presumed to follow the Hixon-Crowell law. If the cube-root dissolution rate constant was found to be 2.49 x 10-2 g^1/3 min^-1, how long (in minutes) will it take for this drug sample to undergo complete dissolution?
A) 4
B) 40
C) 400
D) 400
B) 40